Summary of the Invention
This invention relates to fully automated bag handling and filling machines which pick up bags one at a time from a supply source, fill the bags, draw a vacuum in the bags and release them in an integrated, high speed, and efficient system. More particularly, this invention is drawn to an apparatus for bottom filling and/or vacuum sealing both paper and plastic type bags within a fully automated bag handling and filling machine.
Automated bag handling and filling machines are known in the art. See, for example, U.S. Pat. Nos. 4,322,932, 4,432,186, and 4,612,965 issued to Harold R. McGregor. Traditionally, bag handling and filling machines have utilized bag holding clamps on a clam shell type of filling spout to hold the bag during a filling operation on the spout, with the filled bag then being conveyed to a separate, closing machine for closing the bag top, as by stitching or by heat sealing. Bag control and forming bars have been incorporated to grip the bag mouth, after filling, and to lower it onto a conveyor, which serves to transport the filled bag to a separate, bag closing station. Such bag handling and control bars are shown, for example, in U.S. Pat. No. 4,322,932. Recognizing that operating efficiencies including more compact machine footprints and reduced operational costs could be realized by incorporating the bag sealing function within a single machine for handling, filling, and sealing bags, such integrated machines have been developed. For an example of such an integrated machine see U.S. Pat. No. 5,771,667 issued to Harold R. McGregor.
However, bag sealing apparatuses for such integrated bag handling and filling machines have been limited in the manner in which bags could be filled and closed. Consequently, a bottom filling apparatus for filling bags from the bottom up and a bag sealing apparatus capable of handling and closing both plastic bags and paper bags have been developed. This apparatus has also been adapted for vacuum sealing plastic bags or paper bags with plastic liners.